A persistent and pervasive link has been present between socioeconomic status and health outcomes among adults in the United States. Health literacy is a potential pathway for this link and has been independently associated with decreases in morbidity and mortality. One aspect of literacy that has been little studied is numeracy. Numeracy is defined as having facility with basic probability and mathematical concepts. More numerate patients are more accurate in subjective health risk perceptions and have a better comprehension of risk reduction information. Risk communication is an essential component to important health care interactions including provider- patient communication, informed consent, and shared decision-making. Numeracy may improve the capacity of patients to process risk information, to be active participants in their healthcare, and to believe that health protective behaviors can result in personal benefit over the course of their lives. In this proposal we will explore the relationship between numeracy and the adoption of health protective behaviors including cervical, breast, colon, and prostate cancer screening. The specific aims of this project are: 1. To increase our understanding of the link between numeracy and cognitive, psychological, and decision-making constructs that are relevant to the adoption of health protective behaviors. Cognitive processes evaluted will include knowledge of the risks and benefits of screening behaviors. Psychological traits evaluated will include mastery, general self-efficacy, locus of control, optimism, and trust. Decision-making constructs evaluated will include information seeking and the desire to participate in medical decision-making. 2. To test the association between numeracy and the adoption of cancer screening behaviors, including cervical, breast, colorectal, and prostate cancer screening, while controlling for socioeconomic characteristics. This association will be evaluated in a population of primary care patients that is diverse in educational level, race and ethnicity, income, and age. Our methods will be designed to evaluate the influence of numeracy as a separate construct from formal education and general literacy. While general literacy is related to numeracy, it is certainly not entirely predictive. Literate individuals may have poor numeracy, and numate persons may have poor literacy. The findings will have implications for the role of mathematics in education and the potential role of interventions to improve numeracy among adults.